> Do I take it from Roger's remarks that he has already got J > implemented in J? Or that he would use J to implement J if he > had to do it afresh?
I don't have an implementation of J in J. I proposed it in response to Dan's question. ----- Original Message ----- From: Ian Clark <[email protected]> Date: Wednesday, July 22, 2009 13:34 Subject: Re: [Jprogramming] Reimplementing J To: Programming forum <[email protected]> > Years ago I recall Burroughs staff telling me that the Algol compiler > was itself implemented definitively in Algol -- not just > as a > research tool but operationally, to implement all future releases. > > On my protesting what a crazy thing to do, they assured me it wasn't > as chicken-and-egg as it sounds. You only had to get one working > compiler right at the outset and it can be used to generate a more > advanced compiler, and so on. I recall my history teacher > telling me > that the industrial revolution was founded on the fact that a lathe > could be used to turn the screw to make a closer-tolerance lathe ... > and so on. > > In practice it was one of the most useful "development tools" the > Burroughs people had, because they could bootstrap up new features, > port to new architectures or better implementations of > primitives, and > gave several examples where this had paid off handsomely. Also > from a > staffing point-of-view you don't have to employ specialists in the > "implementation language" because it's the same as the target > language. > > FORTH, if anyone remembers it, was booted-up by "user extension" from > a tiny collection of machine-coded primitives (a sort of one-eyed > p-code), which was partly why it was one of the first languages > to be > ported to new platforms, and indeed was used to implement commercial > operating systems. Not very high-quality ones, I recall. But I don't > think the Burroughs Algol people did it that way: there was no > emulation going on. Nor could they have done it entirely like this: > > PLUS =: + > > The truth lay somewhere between. I would guess though it was basically > PLUS =: + but with the option to replace any definition with a > finer-grained one. Since the generation of a compiler is: source in, > machine-code out, there is no circularity in this. > > Do I take it from Roger's remarks that he has already got J > implemented in J? Or that he would use J to implement J if he > had to > do it afresh? > > Ian > > > On Wed, Jul 22, 2009 at 4:27 PM, Dan Bron<[email protected]> wrote: > > If you were considering reimplementing J, which language would > you use? > > What other tools would you use (e.g. yacc, antlr, parrot VM, etc)? > > > > Assume you're more concerned with productivity than > performance in the > > first instance, but would like the option to tune performance > in the > > future. > > > > What's a good language for implementing other languages? > > > > -Dan ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
